聚乳酸/蒙脱土纳米复合材料的制备及其性能研究

Preparation and Properties of Poly(lactic acid)/Montmorillonite Nano-composites

采用熔融共混法制备聚乳酸/蒙脱土(PLA/MMT)纳米复合材料。用X射线衍射仪、透射电子显微镜、差示扫描量热仪对材料的力学性能、微观结构和形貌进行表征。结果表明,PLA分子链插入MMT片层间,MMT层间距由1.801 nm增大到3.530 nm并呈纳米级均匀分散在PLA基体中,体系相容性良好;MMT的加入量为3%(质量分数,下同)时,复合材料的力学性能得到最大改善,拉伸强度由纯PLA的53.1 MPa提高到62.8 MPa,冲击强度由纯PLA的18.00 kJ/m2提高到23.30 kJ/m2,加入3%MMT的复合材料结晶度为42.63%,试样平均晶粒粒径为0.285 nm,而纯PLA的结晶度是24.52%,平均晶粒粒径0.305 nm,MMT的加入明显提高了PLA的力学性能和结晶度。

Poly（lactic acid）/ montmorillonite （PLA/MMT） nano-composites were prepared through melt intercalation in a twin-screw extruder. The microstructure, morphology, thermal properties, and crystallization behavior of the nano-composites were characterized using XRD, TEM, and DSC. It revealed that the layer spacing of MMT increased from 1.801 to 3.530 nm by the intercalating of PLA. When 3 % of MMT was used, the tensile strength, elongation at break, and impact strength reached the max. With MMT loaded, the degree of crystallinity of PLA increased and the average grain size reduced compared with neat PLA.